Tire mold



Sept. '21', 1926.

S. C. HATFIELD TIRE MOLD Filed Nov. 17. 1922 2 lSheets-Sheet 1 l 3mm/Hoff, i., .QQJ E Sept. 21 1926.

1,600,586 s. c. HATFu-:LD

TIRE MOLD v Filed Nov. 17. 19522 2 Sheets-Sheet 2 UNITED STATES intatte PATENr OFFICE.

SCHUYLER C. HATFIELD, BALTIMORE, MARYLAND.

TIRE MOLD.

factory tread of this type, yand an important object of the present invention is to produce such a tread more perfect and having deeper indeiitations and to produce it more easily and at a smaller cost than previously.

The principal diiiiculties incident4 to the present practice in this particular connection are involved in the removal of the tire from the mold. As the indentations extend at right angles to the aXis or radially and the mold sections are removed in the direction of the axis, the serrations or portions of rubber surrounding the indentations are subject to excessive stress at this time and to accomplish this operation with as little loss as possible, the molds are removed liot when the rubber is softest and most pliable and there is the least tendency to stick and in jure the tread by removal of portions thereof with the mold, but ii'i spite of this practice and the precautions taken, such injuries to the tread are of regular occurrence.4

Numerous tires are sold as seconds on this account, and great difficulty in operation and loss of eiiiciency and expense for labor are encountered on account of the necessity for handling the heavy mold sections While hot.

The present invention relates to a tire mold in which the'difculty asto the formation of the non-skid tread is almostI coinpletely avoided by forming the tread portion of the mold in such a Way as to make it separate from the rest of the mold and in small sections which may be removed radially so that there is no tendency to injure the roughened tread portion of the tire, the relative motion on removing the mold sections being in. the direction of the contacting surfaces which form the sides of the indentations, projections or serratioiis in* stead of at right angles thereto. A Under these circumstances there is no necessity for Application led November 17, 1922. Serial No. 601,659.

removing the mold sections While hot which greatly reduces the difficulty and expense of handling the mold, `and the tread may be made with much deeper serrations than by 50 any previous method.

In the accompanying drawings I have illustrated a tire inold constructed in accordance with my invention.

In the drawings: 65

Figure l is 'a side elevation of the mold.y assembled, looking in the direction of the axis of the Wheel.

Fig. 2 is an elevation 4of the same taken at right angles to Figure 1. I 7@ Fig. El is a side view of a mold section on a larger scale.

Fig. et isa section on the line 4 4 of Fig. 3.

Fig 5 is a section on the line of 5-5 of 7 Fig. 1 on an enlarged scale.

Fig. 6 is a side elevation of a fragmentarv nature and likewise on an enlarged sca-le, showing a tread section with the meeting ends of the tension member by which the 8 treads are held in position.

Fig. 7 is a section on the line 7-7 of Fig. 6. f

referring to the drawing by numerals;

the mold as shown consists of two ring sec- 55 tions 1 and 2, see particularly', Fig. 5 which meet along their inner periphery in a cir cumferential joint 3, which is shown in the .form of a step joint, though this joint may be of any preferred form Within the scope 9 of the invention. The ring sections are substantially duplicates of each other and corresponds as to the meeting surfaces of the joint. These ring sections as hollowed out as to their opposed or neighboring surfaces 95 form an annular chamber 5, adapted to enclose and form a tire, but this chamber 5, is enclosed by these two ring members only 'as to the side Walls on side surfaces 6 and T,

the inner or rim contacting surface 9, being lo@ in the form illustrated, vulcanized into the rim 9 itself, which is enclosed Within the mold and the tread surface 10, being-formed by the separate tread mold member 11, be tween the ring sections l and 2. mold member as shown constitutes a com plete ring intervening and held between the ring sections 1 'and 2, but it is made in arcuate sections which are preferably sufiiciently numerous so that the entire tread mold may M@ be removed substantially in a radial direction.

This tread m5 bolts 24, one of which is passed through each v Eairof ears on the two respective rings, the olts being parallel to the axis of the tire and serving to hold the ring sections together.

rIhe ring sections 1 and 2, are provided at the outer determination of the mold surfaces 6 and 7, thereon with peripheral shoulders 26 on the opposed faces of the ringsadapted to receive and support the tread mold sec' tions 11, and with liat radial peripheral surfaces 27 and 28 on the respective ring sections, adapted to engage and position the side edges, and the tread sections l1, having corresponding fiat annular or peripheral side faces 30 and 3l to enga e the surfaces 27 and 28, of ,the ring mein ers 1 and 2, and

lshoulders 33 and 34 joining and substantially at right anglesto said side surface which shoulders engage the shoulders 26 on the ring member. As shown the shouldersslightly inclined toy on both members are better provide for the positioning of the parts. i p

As shown the tread members 11, are held by encircling cords or cables 35 in circumferential grooves 36, in the outer surfaces of the treadmembers. These tension members or cables 35, are secured at their ends at 38,

right an serve to apply tension to the cables b means of va .right and left handed screw t readed As shown the tread sections 11, are provided each with a screw threaded socket 41 in each by means of which handles or grips 42, having screw threaded Shanks 43, to tit such sockets are secured. These grips are used in handling and withdrawing the tread sections articularly they are used in removing t e tread sections after the molding operation.

In Figure 5, I have shown means for loosening the tire and a rim from the ring mold., -This consists of a plurality of pins 44, seated vin holes 49 in the respective rings 1 and 2, to slide parallel to the axis, i. e. at les to the molding surfaces of these rings an as shown bearing on the rim member 9, to and into which the tire is vulcanized. In the present instance, these pins as shown are four in number in each ring, eight in all, and each of them is actuated by a corresponding screw bolt 45, seated in a threaded aperture 46, which is an extension of and an alignment with the straight aper- Leccese ture 47 in which the 4pin is mounted to slide, the screws of course bein outside so they can force the pins inwar against the rim or tire to 4release it or separate it from the mold.

In operation, the ring members 1 and 2,.

the mold are heated,but this is the only part of the mold it is necessary to heat before assembling. In this way almost the entire eX- pense incident to heatin the mold and handling the heavy mol saved as the'tread sections are small and easy to handle and have special removable grips for this purpose.

After baking or vulcanizing, the tire can be allowed to remain in the mold as long as convenient. A better product is produced by permitting the tire to cool in the mold. As it is necessary to remove the tread portion of the mold sidewise, i. e., in the direction of the axis, a tread with deeper depressions, or longer yor higher projections than -those in the tread of any tiresnow being made can be produced Without injury to the tread and any type of rough tread can be produced with less expense and with a smaller portion of defective tires than by any other apparatus now in use, and because of the fact that all of the heavy parts can be handled cool, the apparatus can be operated more economically than any other equipment for this purpose now known. in turn buckles or similar clamps 39,- which I have thus described specifically and in detail a single lembodiment of my tire mold in order that the nature and o eration of same may be clearly understoo however,

the specific terms herein are used descriptively rather than in a limiting sense, the scope of the invention being defined in the claims.

What I claim and desire to secure by said Letters Patent is:

1. A tire mold consistin of two ring members having annular mo ding surfaces to form the side walls of a tire and a tread mold adapted toV lit' between said ring members which are provided with positioning means to engage the tread mold member, means for drawing the ring members together in the direction the treadmold member being formed in sections so that each section can be removed in a radial direction and circumferentiallyarranged iiexible tension means for holding the sections in position, and means for taking upon said tension means to apply inward radial pressure to said sections of the tread mold members.

2. A tire mold for rough tread tires consections hot is of their axis,

sisting of two ring members having annular molding surfaces to form the side walls of a tire, means for drawing same together in the direction of the axis and atread mol-d having a roughened mold surface and adapted to fit said mold sections in position and means for taking up on said tension means.

3. A. tire mold for rough tread tires consisting of two ringmembers having mold surfaces for the side walls of the tire means for drawing the ring members together, a tread mold to tit between said ring members consisting of a plurality of arcuate sections having a serrated mold surface, and Hexible tension means extending around lthe tread member in a circumferential direction `for holding the sections of the tread member in position and a threaded member for taking up on said flexible tension member.

1l. A tire mold consisting of two ring members having opposed surfaces to form the side walls of a tire and being also formed to receive and support a metal rim on which the tire is formed, a. tread mold member consisting of a plurality of completely sepn arable arcuate sections adapted to be removed in a radio! direction and positioning means on the side Walls for the tread mold member, the tread members having each a socket and a key 'engaging said sockets whereby the arcuate sections may be handled and removed when hot.

5. -A tire mold consisting of two ring members having opposed surfaces for the side walls of a. tire and being also formed to receive and support a metal rim on which the tire is formed, a tread mold member consisting of a plurality of completely separable arcuate sections, each adapted to be removed in a radial direction and positioning means on the side walls for the tread mold member and a flexible tension member encircling said tread member and means in the form of a screw for applying tension thereto to hold the tread member in position and means for securing the ring members together.

Signed by me at Baltimore, Maryland, this 26th day of October, 1922.

, SCHUYLER C. HATFIELD. 

